From cba2dbdb75e91f1cfe9a95367d7cca585eb7b64d Mon Sep 17 00:00:00 2001
From: Anatolii Sakhnik <sakhnik@gmail.com>
Date: Sat, 16 Oct 2021 08:30:44 +0300
Subject: [PATCH] Handle communication errors #12

---
 src/IWindow.hpp      |  1 +
 src/MsgPackRpc.cpp   | 15 ++++++++++++---
 src/MsgPackRpc.hpp   |  5 ++++-
 src/Session.cpp      | 18 +++++++++++++++++-
 src/Session.hpp      |  2 ++
 src/SessionSpawn.cpp |  7 ++-----
 src/Window.hpp       |  2 +-
 7 files changed, 39 insertions(+), 11 deletions(-)

diff --git a/src/IWindow.hpp b/src/IWindow.hpp
index ec03b1f..77dfe2a 100644
--- a/src/IWindow.hpp
+++ b/src/IWindow.hpp
@@ -29,4 +29,5 @@ struct IWindow
 
     virtual void Present() = 0;
     virtual void SessionEnd() = 0;
+    virtual void SetError(const char *) = 0;
 };
diff --git a/src/MsgPackRpc.cpp b/src/MsgPackRpc.cpp
index 408002d..7d8821b 100644
--- a/src/MsgPackRpc.cpp
+++ b/src/MsgPackRpc.cpp
@@ -3,9 +3,11 @@
 #include <iostream>
 
 
-MsgPackRpc::MsgPackRpc(uv_stream_t *stdin_stream, uv_stream_t *stdout_stream)
+MsgPackRpc::MsgPackRpc(uv_stream_t *stdin_stream, uv_stream_t *stdout_stream,
+                       OnErrorT on_error)
     : _stdin_stream{stdin_stream}
     , _stdout_stream{stdout_stream}
+    , _on_error{on_error}
 {
     _stdout_stream->data = this;
 
@@ -17,10 +19,13 @@ MsgPackRpc::MsgPackRpc(uv_stream_t *stdin_stream, uv_stream_t *stdout_stream)
     };
 
     auto read_astream = [](uv_stream_t* stream, ssize_t nread, const uv_buf_t *buf) {
+        MsgPackRpc *self = reinterpret_cast<MsgPackRpc*>(stream->data);
         if (nread > 0)
-        {
-            MsgPackRpc *self = reinterpret_cast<MsgPackRpc*>(stream->data);
             self->_handle_data(buf->base, nread);
+        else
+        {
+            Logger().error("Failed to read: {}", uv_strerror(nread));
+            self->_on_error(uv_strerror(nread));
         }
     };
 
@@ -52,7 +57,11 @@ void MsgPackRpc::Request(PackRequestT pack_request, OnResponseT on_response)
     auto cb = [](uv_write_t* req, int status) {
         Write *w = reinterpret_cast<Write *>(req);
         if (status < 0)
+        {
             Logger().error("Failed to write {} bytes: {}", w->buffer.size(), uv_strerror(status));
+            MsgPackRpc *self = reinterpret_cast<MsgPackRpc *>(req->data);
+            self->_on_error(uv_strerror(status));
+        }
         delete w;
     };
 
diff --git a/src/MsgPackRpc.hpp b/src/MsgPackRpc.hpp
index 5edf0b4..6c3f0b5 100644
--- a/src/MsgPackRpc.hpp
+++ b/src/MsgPackRpc.hpp
@@ -9,7 +9,9 @@
 class MsgPackRpc
 {
 public:
-    MsgPackRpc(uv_stream_t *, uv_stream_t *);
+    using OnErrorT = std::function<void(const char *)>;
+
+    MsgPackRpc(uv_stream_t *, uv_stream_t *, OnErrorT);
     ~MsgPackRpc();
 
     using OnNotificationT = std::function<void(std::string_view, msgpack::object)>;
@@ -31,6 +33,7 @@ class MsgPackRpc
 private:
     uv_stream_t *_stdin_stream;
     uv_stream_t *_stdout_stream;
+    OnErrorT _on_error;
     OnNotificationT _on_notification;
 
     // Capture any non msgpack-rpc output, as it may be text output from --version or alike
diff --git a/src/Session.cpp b/src/Session.cpp
index b1f0143..a0af402 100644
--- a/src/Session.cpp
+++ b/src/Session.cpp
@@ -6,7 +6,8 @@
 
 void Session::_Init(uv_stream_t *in, uv_stream_t *out)
 {
-    _rpc.reset(new MsgPackRpc(in, out));
+    auto onError = [this](const char *error) { _OnError(error); };
+    _rpc.reset(new MsgPackRpc(in, out, onError));
     _renderer.reset(new Renderer{uv_default_loop(), _rpc.get()});
     _redraw_handler.reset(new RedrawHandler{_rpc.get(), _renderer.get()});
 
@@ -45,3 +46,18 @@ void Session::SetWindow(IWindow *window)
     _window = window;
     _renderer->SetWindow(window);
 }
+
+void Session::_OnError(const char *error)
+{
+    _Exit();
+    if (_window && error)
+        _window->SetError(error);
+}
+
+void Session::_Exit()
+{
+    _nvim_exited.store(true, std::memory_order_relaxed);
+    uv_stop(uv_default_loop());
+    if (_window)
+        _window->SessionEnd();
+}
diff --git a/src/Session.hpp b/src/Session.hpp
index 677b9f1..e9055be 100644
--- a/src/Session.hpp
+++ b/src/Session.hpp
@@ -45,4 +45,6 @@ class Session
     IWindow *_window = nullptr;
 
     void _Init(uv_stream_t *in, uv_stream_t *out);
+    void _OnError(const char *);
+    void _Exit();
 };
diff --git a/src/SessionSpawn.cpp b/src/SessionSpawn.cpp
index 75a1fb6..dc4502d 100644
--- a/src/SessionSpawn.cpp
+++ b/src/SessionSpawn.cpp
@@ -24,12 +24,9 @@ SessionSpawn::SessionSpawn(int argc, char *argv[])
     //});
 
     auto on_exit = [](uv_process_t *proc, int64_t exit_status, int signal) {
-        SessionSpawn *session = reinterpret_cast<SessionSpawn *>(proc->data);
         Logger().info("Exit: status={} signal={}", exit_status, signal);
-        session->_nvim_exited.store(true, std::memory_order_relaxed);
-        uv_stop(uv_default_loop());
-        if (session->_window)
-            session->_window->SessionEnd();
+        SessionSpawn *session = reinterpret_cast<SessionSpawn *>(proc->data);
+        session->_Exit();
     };
 
     uv_process_options_t options{};
diff --git a/src/Window.hpp b/src/Window.hpp
index 5f265e4..7bc5201 100644
--- a/src/Window.hpp
+++ b/src/Window.hpp
@@ -21,7 +21,7 @@ class Window
     void DrawCursor(cairo_t *, int row, int col, unsigned fg, std::string_view mode);
     void SessionEnd() override;
 
-    void SetError(const char *error);
+    void SetError(const char *error) override;
 
 private:
     GtkApplication *_app;